Mechanical planters for planting a variety of seeds in furrows in the soil have been known for decades. Various mechanisms have been used for separating and metering the seeds. Although this is relatively easy to do when working with seeds such as corn, beans, etc., this is a very difficult assignment when working with seeds such as potatoes.
One conventional mechanism for metering seed potatoes in mechanical planters involves the use of picks or nails to select the seed from a reservoir or hopper containing seed potatoes. The picks are carried on the ends of movable arms attached to a wheel which rotates through a seed reservoir or hopper. As the wheel rotates, the sharp pick or nail on the outer end of each arm impales or pierces a seed potato and carries it out of the reservoir to a designated point where the seed is to be dropped or released from the pick (e.g., into a seed spout). The arm carrying the pick is cam operated in a manner such that the pick is moved rearwardly relative to a plate through which the pick protrudes. When the pick is moved rearwardly, the seed is forced off from the pick by the plate. When the pick arm rotates into the reservoir again, the pick snaps back to its original position, thereby enabling the pick to impale another seed. There may be more than one pick on each arm, as desired.
The pick mechanism described above is reasonably proficient in picking single seed pieces and in being able to operate accurately at high speeds. Because the picks mechanically pierce the seeds, pick planters are more tolerant of cut seed and uneven seed size.
One disadvantage or drawback of the pick mechanism is that it will not pick rocks out of the seed reservoir. Consequently, the pick will miss a seed each time a rock is in position to be picked when the pick arm snaps forwardly in the reservoir. The rocks can also damage the picks, thereby rendering them useless.
Another disadvantage of the pick mechanism is that more than one seed potato may be impaled on a single arm, resulting in undesirable planting of two seeds in an area in which only one seed is desired.
Yet another disadvantage of the pick mechanism is that the pick has only one opportunity to impale a seed in the hopper (i.e., when the pick snaps forwardly through the plate). If the seed is not properly positioned when the pick snaps forwardly, the seed will not be impaled.
Another type of conventional planter is referred to as a cup planter. This type of planter is very simple and involves cups or scoops mounted on a chain or belt. The seed is selected by running the cup upwardly through the seed reservoir. Multiple seed pieces are typically removed from a single cup by vibrating the belt or chain carrying the cups. The cups do not generally damage the seed as much as the pick. Every function in the cup planter is limited by gravity. It is difficult to singulate the seed at high speed. This results in skips or multiple seed drops. Uneven seed size or shape, especially with cut seed, aggravates the shortcomings of the cup seed meter.
Another type of conventional planter is a grip planter in which a seed is mechanically grasped without piercing it. This type of planter does not damage the seed. However, it has the disadvantage that there is a discreet pick point. If the seed is not in the proper position relative to the grip mechanism, the seed is not grasped.
There has not heretofore been provided planting apparatus having the advantages provided by the apparatus of the present invention.